The three major analog television standards are NTSC, PAL, and SECAM. The National Television System Committee developed the NTSC standard in the U.S. in 1953. NTSC is used in United States, Canada, Japan, in most of the American continent countries, and in various Asian countries. NTSC runs on 525 lines/frame with a vertical frequency of 60 Hz and a framerate of 29.97 frames/sec.
The PAL (Phase Alternating Line) standard was introduced in the early 1960's in Europe. It has better resolution than NTSC, with 625 lines/frame. The framerate is slightly lower than that of NTSC, being 25 frames/sec. PAL is used in most western European countries (except France), Australia, some countries of Africa, some countries of South America, and in some Asian countries.
The SECAM (Sequential Color with Memory) standard was introduced in the early 1960's. SECAM uses the same bandwidth as PAL but transmits the color information sequentially. SECAM runs on 625 lines/frame with a framerate of 25 fps. SECAM is used in France, former French colonies, and in former communist countries in Europe.
Analog video may be received through broadcast, cable, and VCRs. The reception is often corrupted by noise, and therefore to improve the visual quality, noise reduction may be needed. Various noise filters have been utilized in video communication systems and set top boxes. However, inaccurate noise characterization, especially during scenes with motion, can result in artifacts from the filtering that are more visually detrimental than the original noise.
Limitations and disadvantages of conventional and traditional approaches will become apparent to one of ordinary skill in the art through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.